--- ray/src/cv/bsdfrbf.c	2013/10/21 21:48:42	2.13
+++ ray/src/cv/bsdfrbf.c	2014/03/02 01:56:03	2.19
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdfrbf.c,v 2.13 2013/10/21 21:48:42 greg Exp $";
+static const char RCSid[] = "$Id: bsdfrbf.c,v 2.19 2014/03/02 01:56:03 greg Exp $";
 #endif
 /*
  * Radial basis function representation for BSDF data.
@@ -35,7 +35,7 @@ static const char RCSid[] = "$Id: bsdfrbf.c,v 2.13 201
 #define SMOOTH_MSE	5e-5		/* acceptable mean squared error */
 #endif
 #ifndef SMOOTH_MSER
-#define SMOOTH_MSER	0.07		/* acceptable relative MSE */
+#define SMOOTH_MSER	0.03		/* acceptable relative MSE */
 #endif
 #define MAX_RAD		(GRIDRES/8)	/* maximum lobe radius */
 
@@ -91,8 +91,8 @@ add_bsdf_data(double theta_out, double phi_out, double
 static void
 comp_bsdf_min()
 {
-	int	cnt;
-	int	i, target;
+	unsigned long	cnt, target;
+	int		i;
 
 	cnt = 0;
 	for (i = HISTLEN; i--; )
@@ -147,10 +147,11 @@ smooth_region(int x0, int x1, int y0, int y1)
 			xvec[2] += z;
 		}
 	rMtx[1][0] = rMtx[0][1];
+	rMtx[2][0] = rMtx[0][2];
 	rMtx[2][1] = rMtx[1][2];
 	nvs = rMtx[2][2];
 	if (SDinvXform(rMtx, rMtx) != SDEnone)
-		return(0);
+		return(1);		/* colinear values */
 	A = DOT(rMtx[0], xvec);
 	B = DOT(rMtx[1], xvec);
 	C = DOT(rMtx[2], xvec);
@@ -223,7 +224,8 @@ build_rbfrep(RBFVAL **arp, int *np, int x0, int x1, in
 	if (!nleaves)			/* nothing but branches? */
 		return(nadded);
 					/* combine 4 leaves into 1? */
-	if (nleaves == 4 && x1-x0 < MAX_RAD && smooth_region(x0, x1, y0, y1))
+	if ((nleaves == 4) & (x1-x0 <= MAX_RAD) &&
+			smooth_region(x0, x1, y0, y1))
 		return(0);
 					/* need more array space? */
 	if ((*np+nleaves-1)>>RBFALLOCB != (*np-1)>>RBFALLOCB) {